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1.
Small ; : e2400629, 2024 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-38682737

RESUMO

The applications of natural laccases are greatly restricted because of their drawbacks like poor biostability, high costs, and low recovery efficiency. M/NC single atom nanozymes (M/NC SAzymes) are presenting as great substitutes due to their superior enzyme-like activity, excellent selectivity and high stability. In this work, inspired by the catalytic active center of natural enzyme, a biomimetic Fe/NC SAzyme (Fe-SAzyme) with O2-Fe-N4 coordination is successfully developed, exhibiting excellent laccase-like activity. Compared with their natural counterpart, Fe-SAzyme has shown superior catalytic efficiency and excellent stability under a wide range of pH (3.0-9.0), temperature (4-80 °C) and NaCl strength (0-300 mm). Interestingly, density functional theory (DFT) calculations reveal that the high catalytic performance is attributed to the activation of O2 by O2-Fe-N4 sites, which weakened the O─O bonds in the oxygen-to-water oxidation pathway. Furthermore, Fe-SAzyme is successfully applied for efficient aflatoxin B1 removal based on its robust laccase-like catalytic activity. This work provides a strategy for the rational design of laccase-like SAzymes, and the proposed catalytic mechanism will help to understand the coordination environment effect of SAzymes on laccase-like catalytic processes.

2.
Phytochem Anal ; 35(4): 873-888, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38366710

RESUMO

INTRODUCTION: Zhou Tian Formula (ZTF) is an antidepressant traditional Chinese medicine utilized widely in clinical settings for the treatment of patients with depression. However, shortcomings persist in its extraction technology and quality control. OBJECTIVE: This study aimed to propose a methodology for ZTF extraction technology based on the analytic hierarchy process (AHP)-criteria importance through intercriteria correlation (CRITIC) method and to establish a quality control framework for the efficient transfer of index components. METHOD: Firstly, we analyzed the chemical components of ZTF and determined the optimal extraction technology. Secondly, we calculated the transfer efficiency of the index components during the conversion of water decoction to extract powder and subsequently to granules. Thirdly, we established HPLC fingerprints for 15 batches of ZTF water decoction, extract powder, and granules. We employed SIMCA software to analyze the chemicals responsible for variations in quality among different batches of ZTF granules. RESULTS: We determined the optimal extraction process. The average transfer efficiency of ferulic acid, puerarin, mirificin, isoferulic acid, and calycosin during the conversion of water decoction to extract powder and subsequently to granules exceeded 41%. The HPLC fingerprints of ZTF exhibited a similarity exceeding 0.890. Variable importance in projection values indicated that calycosin, ferulic acid, and puerarin were the primary contributors to quality variations. CONCLUSIONS: The AHP-CRITIC method, coupled with an orthogonal array design, could be used for exploring extraction technology. In addition, the rules governing the transfer of index components from water decoction to extract powder, and subsequently to granules, could be applied for the evaluation and quality assessment of ZTF.


Assuntos
Medicamentos de Ervas Chinesas , Cromatografia Líquida de Alta Pressão/métodos , Medicamentos de Ervas Chinesas/química , Controle de Qualidade , Ácidos Cumáricos/química , Ácidos Cumáricos/análise
3.
Cancer ; 129(8): 1195-1204, 2023 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-36748723

RESUMO

BACKGROUND: The authors report results from the thyroid carcinoma cohort of the multicohort phase 2 KEYNOTE-158 study (NCT02628067), which evaluated pembrolizumab monotherapy in patients with previously treated cancers. METHODS: Eligible patients had histologically and/or cytologically confirmed papillary or follicular thyroid carcinoma, failure of or intolerance to prior therapy, and measurable disease per Response Evaluation Criteria in Solid Tumors (RECIST) v1.1. Patients received pembrolizumab (200 mg) every 3 weeks for up to 35 cycles. The primary end point was objective response rate (ORR) per RECIST v1.1 by independent central review. RESULTS: A total of 103 patients were enrolled and received pembrolizumab. Median duration from first dose to data cutoff (October 5, 2020) was 49.4 (range, 43.9-54.9) months. ORR was 6.8% (95% confidence interval [CI], 2.8%-13.5%), and median duration of response was 18.4 (range, 4.2-47.2+) months. ORR was 8.7% (95% CI, 2.4%-20.8%) among patients with programmed cell death ligand 1 (PD-L1) combined positive score (CPS) ≥1 (n = 46) and 5.7% (95% CI, 1.2%-15.7%) among patients with PD-L1 CPS <1 (n = 53). Median overall survival and progression-free survival were 34.5 (95% CI, 21.2 to not reached) and 4.2 (95% CI, 3.9-6.2) months, respectively. Treatment-related adverse events occurred in 69.9% of patients (grade 3-5, 14.6%). CONCLUSIONS: Pembrolizumab demonstrated manageable toxicity and durable antitumor activity in a small subset of patients with advanced thyroid cancer. These results provide evidence of modest antitumor activity in this setting regardless of tumor PD-L1 expression. Future studies evaluating immune checkpoint inhibitors in patients with differentiated thyroid cancer should focus on biomarker-driven patient selection or combination of immune checkpoint inhibitors with other agents, in order to achieve higher response rates than observed in this study.


Assuntos
Adenocarcinoma Folicular , Antineoplásicos Imunológicos , Neoplasias da Glândula Tireoide , Humanos , Inibidores de Checkpoint Imunológico , Antígeno B7-H1 , Antineoplásicos Imunológicos/efeitos adversos , Neoplasias da Glândula Tireoide/tratamento farmacológico , Adenocarcinoma Folicular/tratamento farmacológico
4.
J Environ Manage ; 340: 117959, 2023 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-37100002

RESUMO

Water environmental management (WEM) has a significant influence on the global ecological balance. As an institutional innovation, the River Chief System (RCS) in China has achieved a positive short-term impact on addressing water environmental problems. However, its effects are limited in rural China. As a type of public good, the rural WEM demands the active participation not only of government but also of farmers. Based on the social cognitive and social network theory, this study empirically investigates how rural social networks promote farmers' participation in WEM. Using the survey of 860 farmers in the Yellow and Yangtze River Basin, we employ the double-hurdle model (D-H-M) to craft the primary assessment. The results show that the social network embeddedness facilitates farmers' participation in WEM directly. Collective efficacy plays a full mediation role in the relationship between social network embeddedness and farmers' participation. Moreover, the perceived role of village leaders affects the relationship between social networks and farmers' participation. Our research enriches the application of social network theory in the rural social context and offers an innovative approach to solving farmers' participation problems in WEM.


Assuntos
Agricultura , Conservação dos Recursos Naturais , Humanos , Fazendeiros/psicologia , Eficácia Coletiva , China , Rede Social
5.
J Sci Food Agric ; 103(12): 6025-6032, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37200217

RESUMO

BACKGROUND: Species adulteration has been widely revealed around the world, and the possible reasons include declining stocks in most source areas of the world, poor transparency in the global supply chain, and difficulty in distinguishing the features of processed products. The present work selected Atlantic cod (Gadus morhua) as a case study, and developed a novel loop-mediated isothermal amplification (LAMP) assay for Atlantic cod authentication, where a self-quenched primer and a newly designed reaction vessel were used to realize the endpoint visual detection of the target-specific products. RESULTS: A novel LAMP primer set was designed for Atlantic cod, and the inner primer BIP was selected to label the self-quenched fluorogenic element. The fluorophore's dequenching only occurred along with LAMP elongation for the target species. No fluorescence could be observed with both single-stranded DNA and partially complementary dsDNA of the non-target species. With the novel reaction vessel, both amplification as well as detection were operated in an enclosed device, and visual differentiation of Atlantic cod, negative control, and false positive generated from primer dimers was achieved. The novel assay has proved its specificity and applicability, and could detect as little as 1 pg of Atlantic cod DNA. Moreover, Atlantic cod adulteration as low as 10% could be detected in haddock (Melanogrammus aeglefinus), and no cross-reactivity was observed. CONCLUSION: The established assay could be a useful tool to detect mislabeling incidents involving Atlantic cod considering the advantages of speed, simplicity and accuracy. © 2023 Society of Chemical Industry.


Assuntos
Gadiformes , Gadus morhua , Animais , Gadus morhua/genética , Técnicas de Amplificação de Ácido Nucleico , Gadiformes/genética , Técnicas de Diagnóstico Molecular
6.
Opt Express ; 30(15): 27704-27714, 2022 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-36236936

RESUMO

We propose and experimentally demonstrate a fiber refractometer based on a C-shaped fiber and the Vernier effect. The sensor is fabricated by cascading a single mode fiber (SMF) pigtail together with a C-shaped fiber segment and another SMF segment. Thus, the C-shaped fiber would constitute an open cavity (sensing cavity) in which test analytes could be filled, while the SMF segment would constitute another reference cavity. Due to the similar optical path length of these two cavities, the Vernier effect would be activated, thus forming spectral envelops in the reflection spectrum of the sensor. Variations in the refractive index (RI) of analytes would result in the shifts of the spectral envelops. Both theoretical calculations and experiments are carried out in the characterization of the sensor measuring liquid and gaseous analytes. The experimental sensitivity of the sensor is found to be ∼37238 nm/RIU for gas RI measurement. The proposed sensor features the advantages such as ease of fabrication, extremely high sensitivity, capability of sensing of both gaseous and liquid analytes, small footprint, and good mechanical strength. Compared to other existing Vernier effect-based fiber refractometers typically fabricated using PCFs, the proposed sensor would allow analytes to have much easier and quicker access to the sensor probe.

7.
Microvasc Res ; 143: 104400, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35724741

RESUMO

Accumulating evidences have pointed that foxc1a is essential for vascular development and integrity maintenance through regulating the expression of downstream genes and interacting with signaling pathways. However, the underling cellular and molecular mechanisms of foxc1a in regulating vascular development remain undetermined. Based on two different foxc1a mutant zebrafish lines (foxc1anju18 and foxc1anju19 which generated predicted truncated foxc1a proteins with 50aa and 315aa respectively), we found that around 30 % of foxc1anju18 zebrafish exhibited severe vascular developmental defects with obvious hemorrhage in hindbrain and trunk at embryonic stages. Confocal imaging analysis revealed that the formation of middle cerebral vein (MCeV), intra-cerebral central arteries (CtAs) and dorsal longitudinal vein (DLV) of brain vessels was significantly blocked in foxc1anju18enbryos. Injection of exogenous full length and foxc1anju19 truncated foxc1a mRNA both rescued the deficiency of foxc1anju18 embryos. Transcriptome analysis revealed 186 DEGs in foxc1anju18 zebrafish among which amotl2a and ctnnb1 expression were reduced and functionally associated with adherens junctions. Dual-Luciferase assays validated amotl2a and ctnnb1 were both directly transactivated by foxc1a. Rescue experiments demonstrated that amotl2a was mainly responsible for the vascular integrity caused by foxc1a mutation and also coordinated with ctnnb1 to regulate brain vascular development. Our data point to a novel clue that foxc1a regulates vascular integrity and brain vascular development through targeting amotl2a and ctnnb1.


Assuntos
Proteínas de Peixe-Zebra , Peixe-Zebra , Animais , Encéfalo/metabolismo , Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Transdução de Sinais , Peixe-Zebra/genética , Peixe-Zebra/metabolismo , Proteínas de Peixe-Zebra/genética , Proteínas de Peixe-Zebra/metabolismo
8.
BMC Cancer ; 22(1): 488, 2022 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-35505294

RESUMO

BACKGROUND: Emerging evidence has identified miR-138 as a tumor suppressor that can suppress the proliferation of various cancers. Meanwhile, the cause of abnormal miR-138 expression in cervical cancer remains uncertain. This study clarified the mechanism by which miR-138 regulates proliferation, invasion, metastasis, and EMT in cervical cancer cells. RESULTS: miR-138 expression in human cervical cancer and adjacent normal tissue was measured using qPCR. SiHa and C33A cells were used to determine the function of miR-138 via miR-138 mimic or inhibitor transfection, followed by wound healing, Cell Counting Kit-8, flow cytometry, and Transwell assays. Epithelial and mesenchymal marker expression was analyzed using Western blotting. DNA methylation in the miR-138 promoter was examined using bisulfite sequencing PCR. The downstream target genes of miR-138 were identified via bioinformatics analysis and luciferase reporter assays. A tumor xenograft model was employed to validate DNA methylation-induced miR-138 downregulation and tumor growth inhibition in cervical cancer in vivo. miR-138 levels were significantly lower in cervical cancer tissues than in adjacent control tissues. Furthermore, lower miR-138 expression and higher CpG methylation in the miR-138 promoter were identified in lymph node-positive metastatic cervical cancer tumors versus that in non-metastatic tumor tissues. Upon miR-138 overexpression, cell proliferation, metastasis, invasion, and EMT were suppressed. miR-138 agomir transfection and demethylating drug treatment significantly inhibited cervical tumor growth and EMT in tumor xenograft models. DNA methylation inhibited miR-138 transcription, and enhancer of zeste homolog 2 (EZH2) downregulation mediated the tumor suppressor function of miR-138 in cervical cancer. CONCLUSION: We demonstrated that miR-138 suppresses tumor progression by targeting EZH2 in cervical cancer and uncovered the role of DNA methylation in the miR-138 promoter in its downregulation. These findings demonstrated the potential of miR-138 to predict disease metastasis and/or function as a therapeutic target in cervical cancer.


Assuntos
Metilação de DNA , MicroRNAs , Neoplasias do Colo do Útero , Linhagem Celular Tumoral , Proliferação de Células , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Transição Epitelial-Mesenquimal , Feminino , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , Neoplasias do Colo do Útero/genética , Neoplasias do Colo do Útero/patologia
9.
Nucleic Acids Res ; 48(19): 10680-10690, 2020 11 04.
Artigo em Inglês | MEDLINE | ID: mdl-33021630

RESUMO

Circular DNA aptamers are powerful candidates for therapeutic applications given their dramatically enhanced biostability. Herein we report the first effort to evolve circular DNA aptamers that bind a human protein directly in serum, a complex biofluid. Targeting human thrombin, this strategy has led to the discovery of a circular aptamer, named CTBA4T-B1, that exhibits very high binding affinity (with a dissociation constant of 19 pM), excellent anticoagulation activity (with the half maximal inhibitory concentration of 90 pM) and high stability (with a half-life of 8 h) in human serum, highlighting the advantage of performing aptamer selection directly in the environment where the application is intended. CTBA4T-B1 is predicted to adopt a unique structural fold with a central two-tiered guanine quadruplex capped by two long stem-loops. This structural arrangement differs from all known thrombin binding linear DNA aptamers, demonstrating the added advantage of evolving aptamers from circular DNA libraries. The method described here permits the derivation of circular DNA aptamers directly in biological fluids and could potentially be adapted to generate other types of aptamers for therapeutic applications.


Assuntos
Aptâmeros de Nucleotídeos/química , DNA Circular/química , Trombina/metabolismo , Aptâmeros de Nucleotídeos/sangue , Aptâmeros de Nucleotídeos/metabolismo , DNA Circular/sangue , DNA Circular/metabolismo , Quadruplex G , Humanos , Ligação Proteica , Trombina/química
10.
Arch Gynecol Obstet ; 306(6): 2047-2054, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36006486

RESUMO

PURPOSE: The study aims to investigate the relationship between endometrial thickening and endometrial lesions in postmenopausal women. METHODS: Totally 390 postmenopausal patients with endometrial thickening ≥ 5 mm were enrolled from June 2016 to April 2020, among whom 188 patients were asymptomatic and 202 patients were symptomatic. RESULTS: There were 50 cases with endometrial cancer and precancerous lesions and 150 cases with benign lesions in the symptomatic group, significantly higher than that in the asymptomatic group. The most common pathological type in the asymptomatic group was endometrial polyp. In the asymptomatic group, statistically significant differences were found in endometrial thickness between patients with endometrial cancer and precancerous lesion (group B) and those with benign lesions and non-organic lesions (group A). Statistically significant differences were also found in age, endometrial thickness, hypertension, full-term delivery time and miscarriage times between group A and group B. Regression analysis indicated that hypertension and endometrial thickness were independent risk factors for endometrial cancer and precancerous lesions in the symptomatic group. ROC analysis showed that 10.5 mm was the optimal threshold for predicting endometrial cancer and precancerous lesions in the asymptomatic group, with sensitivity of 100% and specificity of 78.3%. CONCLUSION: The incidence of endometrial cancer and precancerous lesions in postmenopausal women with endometrial thickening and vaginal bleeding is higher than that of asymptomatic women. The endometrial thickening in postmenopausal asymptomatic women is mainly benign, and the threshold for predicting endometrial cancer and precancerous lesions is 10.5 mm.


Assuntos
Neoplasias do Endométrio , Hipertensão , Lesões Pré-Cancerosas , Doenças Uterinas , Humanos , Feminino , Endométrio/diagnóstico por imagem , Endométrio/patologia , Pós-Menopausa , Ultrassonografia , Doenças Uterinas/diagnóstico por imagem , Doenças Uterinas/epidemiologia , Doenças Uterinas/patologia , Neoplasias do Endométrio/epidemiologia , Neoplasias do Endométrio/patologia , Hemorragia Uterina/etiologia , Hemorragia Uterina/patologia , Lesões Pré-Cancerosas/patologia
11.
Cancer Cell Int ; 21(1): 36, 2021 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-33422081

RESUMO

BACKGROUND: Long non-coding RNAs (lncRNAs) are pervasively transcribed in genome and emerging as a new player in tumorigenesis due to their functions in transcriptional, posttranscriptional and epigenetic mechanisms of gene regulation. As the most frequent malignancy and the foremost source of cancer mortality, lung cancer is a heterogeneous disorder. The most common type of lung cancer is Non-small cell lung cancer (NSCLC), occupying 85% of the total cases, and the main subtypes of NSCLC include lung adenocarcinoma (LAD), large cell carcinoma (LCC), and lung squamous cell carcinoma (LSCC). Recently, numerous lncRNAs have been reported to be strongly linked to NSCLC. In the present study, we found that a new lncRNA CBR3-AS1 is highly expressed in lung cancer. In addition, we also examined the expression of lncRNA CBR3-AS1 in 60 of LADs, 40 of LCCs and 40 of LSCCs patient samples, finding that CBR3-AS1 was specificity highly expressed in LAD cancer tissues. Mechanically, we discovered that CBR3-AS1 could regulate the proliferation, migration and invasion of LAD cells through targeting Wnt/ß-catenin signaling. METHODS: Real-time PCR, RNA-pulldown, RIP, western blotting, lentivirus transfection, luciferase reporter assays, cell proliferation assays, colony formation assays, wound healing scratch assays and transwell assays were employed to examine the relationship between lncRNA CBR3-AS1 and its regulation of Wnt/ß-catenin signaling in LAD cells. RESULTS: LncRNA CBR3-AS1 is highly-expressed in LAD and cell lines. LncRNA CBR3-AS1 shows physical association with ß-catenin. CBR3-AS1 could facilitate Wnt/ß-catenin signaling activation thought promoting nuclear localization of ß-catenin. CBR3-AS1 promotes LAD cell proliferation, migration and invasion by targeting Wnt/ß-catenin signaling. CONCLUSION: It can be found that a new functional lncRNA CBR3-AS1 could promote nuclear localization of ß-catenin so as to facilitate Wnt/ß-catenin signaling activation and regulate the proliferation, migration and invasion of LAD cells.

12.
Appl Microbiol Biotechnol ; 105(10): 4127-4140, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33990858

RESUMO

Gamma-aminobutyric acid (GABA), an important bioactive compound, is synthesized through the decarboxylation of L-glutamate (L-Glu) by glutamate decarboxylase (GAD). The use of lactic acid bacteria (LAB) as catalysts opens interesting avenues for the biosynthesis of food-grade GABA. However, a key obstacle involved in the improvement of GABA production is how to resolve the discrepancy of optimal pH between the intracellular GAD activity and cell growth. In this work, a potential GAD candidate (LpGadB) from Lactobacillus plantarum was heterologously expressed in Escherichia coli. Recombinant LpGadB existed as a homodimer under the native conditions with a molecular mass of 109.6 kDa and exhibited maximal activity at 40°C and pH 5.0. The Km value and catalytic efficiency (kcat/Km) of LpGadB for L-Glu was 21.33 mM and 1.19 mM-1s-1, respectively, with the specific activity of 26.67 µM/min/mg protein. Subsequently, four C-terminally truncated LpGadB mutants (GadBΔC10, GadBΔC11, GadBΔC12, GadBΔC13) were constructed based on homology modeling. Among them, the mutant GadBΔC11 with highest catalytic activity at near-neutral pH values was selected. In further, the GadBΔC11 and Glu/GABA antiporter (GadC) of Lactococcus lactis were co-overexpressed in the host L. lactis NZ3900. Finally, after 48 h of batch fermentation, the engineered strain L. lactis NZ3900/pNZ8149-gadBΔC11C yielded GABA concentration up to 33.52 g/L by applying a two-stage pH control strategy. Remarkably, this is the highest yield obtained to date for GABA from fermentation with L. lactis as a microbial cell factory.Key points• The GadB from L. plantarum was heterologously expressed in E. coli and biochemically characterized.• Deletion of the C-plug in GadB shifted its pH-dependent activity toward a higher pH.• Reconstructing the GAD system of L. lactis is an effective approach for improving its GABA production.


Assuntos
Glutamato Descarboxilase , Lactococcus lactis , Escherichia coli/genética , Glutamato Descarboxilase/genética , Ácido Glutâmico , Lactococcus lactis/genética , Ácido gama-Aminobutírico
13.
Health Expect ; 24(6): 2087-2097, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34510675

RESUMO

BACKGROUND: The most common and severe type of nosocomial infection in patients with colorectal cancer is surgical site infection (SSI). Patient-related factors are an important components of SSI. So it is necessary to participate in SSI prevention and control. It is important to identify the factors that influence patients' participation behaviour and to explore the mechanism of these effects. METHODS: A total of 580 patients with colorectal cancer completed relevant measures. Based on the extended theory of planned behaviour, a structural equation model was used to analyse the relationship among the influencing factors. RESULTS: The factors influencing participation of patients with colorectal cancer in SSI prevention and control were participation intention, participation ability, self-efficacy, participation attitude, perceived medical staff support, trust in physicians and social support. The direct effect coefficients of participation intention, participation ability and physician trust on SSI prevention and control behaviour were 0.67, 0.21 and 0.11, respectively. Self-efficacy, participation attitude, perceived medical staff support and social support indirectly affect participation behaviour through participation intention, and their effect values are 0.21, 0.11, 0.11 and 0.08, respectively. CONCLUSIONS: Based on the structural equation model developed in this study, targeted intervention measures should be implemented to mobilize the intention and enthusiasm of patients with colorectal cancer to participate in the prevention and control of SSI. PATIENT OR PUBLIC CONTRIBUTION: Patients or public contribute to spreading research findings, and promote broad participation in the implementation of policies or strategies.


Assuntos
Neoplasias Colorretais , Infecção da Ferida Cirúrgica , Atitude , Neoplasias Colorretais/cirurgia , Humanos , Intenção , Apoio Social , Infecção da Ferida Cirúrgica/prevenção & controle
14.
Biotechnol Lett ; 43(10): 2027-2034, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34308525

RESUMO

OBJECTIVES: γ-amino butyric acid (GABA) is a non-protein amino acid, considered a potent bioactive compound. This study focused on biosynthesis of food-grade GABA by immobilized glutamate decarboxylase (GAD) from Lactobacillus plantarum in the rice vinegar and monosodium glutamate (MSG) reaction system. RESULTS: The gene encoding glutamate decarboxylase (GadB) from L. plantarum has been heterologously expressed in Lactococcus lactis and biochemically characterized. Recombinant GadB existed as a homodimer, and displayed maximal activity at 40 °C and pH 5.0. The Km value and catalytic efficiency (kcat/Km) of GadB for L-Glu was 22.33 mM and 62.4 mM-1 min-1, respectively, with a specific activity of 24.97 U/mg protein. Then, purified GadB was encapsulated in gellan gum beads. Compared to the free enzyme, immobilized GadB showed higher operational and storage stability. Finally, 9.82 to 21.48 g/L of GABA have been acquired by regulating the amounts of catalyst microspheres ranging from 0.5 to 0.8 g (wet weight) in 0.8 mL of the designed rice vinegar and MSG reaction system. CONCLUSIONS: The method of production GABA by immobilized GadB microspheres mixed in the rice vinegar and MSG reaction system is introduced herein for the first time. Especially, the results obtained here meet the increased interest in the harnessing of biocatalyst to synthesize food-grade GABA.


Assuntos
Proteínas de Bactérias/metabolismo , Enzimas Imobilizadas/metabolismo , Glutamato Descarboxilase/metabolismo , Lactobacillus plantarum/enzimologia , Ácido gama-Aminobutírico/metabolismo , Ácido Acético/química , Estabilidade Enzimática , Oryza , Polissacarídeos Bacterianos/química , Glutamato de Sódio/química
15.
J Perianesth Nurs ; 36(6): 724-729, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34663532

RESUMO

PURPOSES: Inadvertent intraoperative hypothermia (core temperature <36°C) is a common surgical complication with several adverse events. Hypothermia prediction models can be a tool for providing the healthcare staff with information on the risk of inadvertent hypothermia. Our systematic review aimed to identify, demonstrate, and evaluate the available intraoperative hypothermia risk prediction models in surgical populations. DESIGN: This study is a systematic review of literature. METHODS: We systematically searched multiple databases (Ovid MEDLINE, Web of Science, Embase, and Cochrane Center Register of Controlled Trials). Two reviewers independently examined abstracts and the full text for eligibility. Data collection was guided by the CHecklist for critical Appraisal and data extraction for systematic Reviews of prediction Modelling Studies (CHARMS checklist), and methodological quality and applicability were assessed by the Prediction model Risk Of Bias ASsessment Tool (PROBAST). FINDINGS: A total of 3,672 references were screened, of which eight articles were included in this study. All the models had a high risk of bias since most of them lacked model validation. Also, they failed to report the model performance and final model presentations, which restricted their clinical application. CONCLUSIONS: The researchers should present models in a more standard way and improve the existing models to increase their predictive values for clinical application.


Assuntos
Hipotermia , Viés , Humanos , Hipotermia/etiologia , Medição de Risco
16.
Microb Cell Fact ; 18(1): 206, 2019 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-31775761

RESUMO

BACKGROUND: The choice of phosphate/nitrogen source and their concentrations have been shown to have great influences on antibiotic production. However, the underlying mechanisms responsible for this remain poorly understood. RESULTS: We show that nutrient-sensing regulator PhoP (phosphate regulator) binds to and upregulates most of genes (ery cluster genes) involved in erythromycin biosynthesis in Saccharopolyspora erythraea, resulting in increase of erythromycin yield. Furthermore, it was found that PhoP also directly interacted with the promoter region of bldD gene encoding an activator of erythromycin biosynthesis, and induced its transcription. Phosphate limitation and overexpression of phoP increased the transcript levels of ery genes to enhance the erythromycin production. The results are further supported by observation that an over-producing strain of S. erythraea expressed more PhoP than a wild-type strain. On the other hand, nitrogen signal exerts the regulatory effect on the erythromycin biosynthesis through GlnR negatively regulating the transcription of phoP gene. CONCLUSIONS: These findings provide evidence that PhoP mediates the interplay between phosphate/nitrogen metabolism and secondary metabolism by integrating phosphate/nitrogen signals to modulate the erythromycin biosynthesis. Our study reveals a molecular mechanism underlying antibiotic production, and suggests new possibilities for designing metabolic engineering and fermentation optimization strategies for increasing antibiotics yield.


Assuntos
Proteínas de Bactérias/metabolismo , Eritromicina/biossíntese , Saccharopolyspora , Antibacterianos/biossíntese , Regulação Bacteriana da Expressão Gênica , Engenharia Metabólica , Fosfatos/metabolismo , Saccharopolyspora/genética , Saccharopolyspora/metabolismo , Fatores de Transcrição/genética
17.
Bioorg Med Chem Lett ; 29(8): 1001-1006, 2019 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-30803804

RESUMO

The discovery, structure-activity relationships, and optimization of a novel class of fatty acid synthase (FASN) inhibitors is reported. High throughput screening identified a series of substituted piperazines with structural features that enable interactions with many of the potency-driving regions of the FASN KR domain binding site. Derived from this series was FT113, a compound with potent biochemical and cellular activity, which translated into excellent activity in in vivo models.


Assuntos
Ácido Graxo Sintases/antagonistas & inibidores , Piperazinas/química , Administração Oral , Animais , Sítios de Ligação , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Avaliação Pré-Clínica de Medicamentos , Ácido Graxo Sintases/metabolismo , Meia-Vida , Humanos , Malonil Coenzima A/metabolismo , Camundongos , Camundongos Nus , Simulação de Acoplamento Molecular , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Piperazinas/administração & dosagem , Piperazinas/farmacocinética , Piperazinas/farmacologia , Estrutura Terciária de Proteína , Ratos , Relação Estrutura-Atividade
18.
Sensors (Basel) ; 19(4)2019 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-30781552

RESUMO

Unmanned aerial vehicles (UAVs) equipped with dual-band crop-growth sensors can achieve high-throughput acquisition of crop-growth information. However, the downwash airflow field of the UAV disturbs the crop canopy during sensor measurements. To resolve this issue, we used computational fluid dynamics (CFD), numerical simulation, and three-dimensional airflow field testers to study the UAV-borne multispectral-sensor method for monitoring crop growth. The results show that when the flying height of the UAV is 1 m from the crop canopy, the generated airflow field on the surface of the crop canopy is elliptical, with a long semiaxis length of about 0.45 m and a short semiaxis of about 0.4 m. The flow-field distribution results, combined with the sensor's field of view, indicated that the support length of the UAV-borne multispectral sensor should be 0.6 m. Wheat test results showed that the ratio vegetation index (RVI) output of the UAV-borne spectral sensor had a linear fit coefficient of determination (R²) of 0.81, and a root mean square error (RMSE) of 0.38 compared with the ASD Fieldspec2 spectrometer. Our method improves the accuracy and stability of measurement results of the UAV-borne dual-band crop-growth sensor. Rice test results showed that the RVI value measured by the UAV-borne multispectral sensor had good linearity with leaf nitrogen accumulation (LNA), leaf area index (LAI), and leaf dry weight (LDW); R² was 0.62, 0.76, and 0.60, and RMSE was 2.28, 1.03, and 10.73, respectively. Our monitoring method could be well-applied to UAV-borne dual-band crop growth sensors.


Assuntos
Técnicas Biossensoriais , Produtos Agrícolas/fisiologia , Monitorização Fisiológica/métodos , Tecnologia de Sensoriamento Remoto/métodos , Nitrogênio/metabolismo , Oryza/crescimento & desenvolvimento , Triticum/crescimento & desenvolvimento
19.
Bioorg Med Chem Lett ; 28(12): 2143-2147, 2018 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-29776742

RESUMO

N-Hydroxy-2-arylisoindoline-4-carboxamides are potent and selective inhibitors of HDAC11. The discovery, synthesis, and structure activity relationships of this novel series of inhibitors are reported. An advanced analog (FT895) displays promising cellular activity and pharmacokinetic properties that make it a useful tool to study the biology of HDAC11 and its potential use as a therapeutic target for oncology and inflammation indications.


Assuntos
Descoberta de Drogas , Inibidores Enzimáticos/farmacologia , Histona Desacetilases/metabolismo , Isoindóis/farmacologia , Animais , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Humanos , Isoindóis/síntese química , Isoindóis/química , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Estrutura Molecular , Proteínas Recombinantes/metabolismo , Relação Estrutura-Atividade
20.
Inorg Chem ; 57(14): 8375-8381, 2018 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-29952566

RESUMO

Ternary CuZnS nanocrystals (NCs) are synthesized via a facile, scalable, noninjection method at low temperatures for the first time, wherein sodium ascorbate plays the dual roles of reducing agent and capping ligand in the preparation process. These NCs can be dispersed well in a polar solvent like dimethyl sulfoxide, and the average size is ∼4 nm as measured by transmission electron microscopy. The results of X-ray diffraction and X-ray photoelectron spectroscopy indicate that the crystal structure of CuZnS NCs displays covellite CuS-like structure and the Zn element partly occupies the Cu position. Also, the crystal structure of CuZnS NCs is completely converted from a covellite CuS structure into a digenite Cu9S5 structure when the NCs are treated above 350 °C. Moreover, CuZnS NCs demonstrate favorable hole transport properties. When it is employed in MAPbI3-based perovskite solar cells as a hole transport layer, a peak power conversion efficiency of 18.3% is achieved. Simultaneously, the devices based on CuZnS exhibit a remarkably reduced J-V hysteresis. The results indicate that CuZnS is a promising hole transport layer for enhancing perovskite solar cell performance and presents great potential for optoelectronic applications, as well.

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